1. Field of the Invention
The present invention relates to a current driving circuit and related control method, and more particularly to a current driving circuit having a small and stable leakage current, and a control method thereof.
2. Description of the Prior Art
A current driving circuit is utilized to generate a large current according to an input voltage. To sustain the large current, an output stage of the current driving circuit is designed to have a large size. In other words, the driving transistors of the output stage possess a large aspect ratio (Width/Length, W/L). Since the driving capability of the output stage transistors is strong, a malfunction current will be induced, which may seriously affect the normal operation of the whole system connected to the current driving circuit. For example, when the output terminal of the current driving circuit is misconnected to the ground voltage or the supply voltage, a large error-current may be induced to flow through the driving transistor between the ground voltage and the output terminal, or through the driving transistor between the supply voltage and the output terminal. This large error-current will damage the path between the driving transistor and the ground voltage, or the path between the driving transistor and the supply voltage. Moreover, the large error-current may shift the voltage level of the ground voltage or the supply voltage by an offset voltage such that the other functional circuits coupled to the ground voltage or the supply voltage will be affected, thereby generating malfunctions. Providing an efficient and stable current detecting method for a current driving circuit is therefore a significant concern in the field of current drivers.